1. Hormones,
The Perfect
Storm?
Introduction
♦ How do the endocrine and nervous systems work
together? (1)
The endocrine and nervous systems function to
achieve homeostasis
When the two systems work together, referred to as the
neuroendocrine system, they perform the same general
functions: communication, integration, and control.
♦ What is the method in which the endocrine system
undergoes its functions? (1)
In the endocrine system, secreting cells send
hormone molecules via the blood to specific target cells
contained in target tissues of target organs
Hormones- carried to almost every point in the body; can
regulate most cells; effects work more slowly and last
longer than those of neurotransmitters
Endocrine glands are “ductless glands”; many are made of
glandular epithelium whose cells manufacture and secrete
hormones; a few endocrine glands are made of
neurosecretory tissue
Glands of the endocrine system are widely scattered
throughout the body.
Ashley, Nathan, Katherine, Shannon, Gentry Anatomy & Physiology
Group B7

2. ♦ PANCREATIC ISLETS- The pancreatic islets are composed of endocrine
ISLETS-
and exocrine tissues. pancreatic islets- endocrine portion. acini-exocrine
Function, portion- secretes a serous fluid containing digestive enzymes into ducts
Structure, Hormones draining into the small intestine. each islet contains four primary types
of endocrine glands joined by a gap junctions. alpha cells (secrete
glucagon), beta cells (secrete insulin; account for up to 75% of all pan-
Hormones ♦ PROSTAGLANDS: They are any member of a group of lipid compounds that
creatic islet cells), delta cells( secrete somatostatin), Pancreatic polypep-
are formed enzymatically from fatty acids. These aren’t endocrine hormones
tide cells (secrete pancreatic polypeptides). Pancreatic hormones work
yet autocrine or paracrine which play a role of locally acting messenger tools. as a team to maintain homeostasis of food molecules. Glucagon
♦ FUNCTION
The functions of the prostaglands are to serve as mediators and having nu- (produced by alpha cells) tends to increase blood glucose levels; stimu-
Tropic hormones are hormones that target other endocrine merous physiological effects like the relaxation and contraction of small lates gluconeogenesis in liver cells. Insulin (produced by beta cells)
glands and stimulate their growth and secretion. muscle tissue. Also, they control cell growth, hormone regulation, induce lowers blood concentration of glucose, amino acids, and fatty acids and
labor, cause aggression and disaggregation and so much more. Prostaglands promotes their metabolism by tissue cells. Somatostatin (produced by
Sex hormones are hormones that target reproductive tissues. can be found in seminal fluid, the central nervous system, and microsomes. delta cells) primary role is regulating the other endocrinie cells of the
(1) pancreatic islets. Pancreatic polypeptide (produced by F cells) influences
Anabolic hormones are hormones that stimulate anabolism in
the digestion and distribution of food molecules to some degree.(1)
target cells. (1)
♦ PITUITARY GLAND: The pituitary gland is located at the base of the brain, and
♦ GONADS-
GONADS- The Testes- paired organs within the scrotum in the male are
♦ STRUCTURE is part of the endocrine system. It has the function of regulating growth, telling
composed of seminiferous tubules and a scattering of interstitial cells.
your brain when to stop growing. Several Hormones that are associated with testosterone ins produced by the interstitial cells and responsible for the
Steroid hormones are synthesized from cholesterol. They are the Pituitary gland would be FSH, in charge of the release of estrogen for growth and maintenance of male sexual characteristics. testosterone
lipid soluble and can easily pass through the phospholipid females and spermatogonia; LH triggers the completion of meiosis of an egg secretion is mainly regulated by gonadotropin levels in the blood. The
plasma membrane or target cells. Examples of steroid hor- and the release of the egg during the menstrual cycle, for the men LH acts on ovaries-primary sex organs in the female are a set of paired glands in
mones include cortisol, aldosterone, estrogen, progesterone the Leydig cells, stimulating them to release testosterone. (1 the pelvis that produce several types of sex hormones. estrogens- ster-
and testosterone.(1) oid hormones secreted by ovarian follicles; promote development and
♦ Pineal Gland: It is located between the cerebral hemisphere and the third maintenance of female sexual characteristics. progesterone- secreted
Nonsteroid hormones are synthesized primarily from amino
ventricle also being a part of the diencephalon structure of the brain. The by corpus luteum; maintains the lining of the uterus necessary for
acids. Protein hormones are long folded chains of amino
pineal gland is what connects the endocrine system with the nervous system, successful pregnancy. ovarian hormone secretion depends on the
acids like insulin and parathyroid hormone. Also included are changing levels of FSH and LH from the adenohypophysis.(1)
converting nerve signals into hormone signals. Hormones released from the
Glycoprotein hormones which are protein hormones with a
pineal gland are melatonin, influencing sexual development as well as sleep ♦ PLACENTA- The placeta is the tissues that form on the lining of the
PLACENTA-
carbohydrate groups attached to the amino acid chain. (1)
wake cycles. (1) uterus as a connection between the circulatory system of the mother
Peptide hormones are smaller than protein hormones, they and developing child. It serves as a temporary endocrine gland that
are a short chain of amino acids. Peptide hormones oxytocin ♦ Thyroid Gland: Located right above the hypothalamus, they thyroid gland plays produces human chorionic gonadotropin, estrogens, and progester-
and antidiuretic hormone (ADH) (1) a major role in regulating the body’s metabolism. It controls how the body one.(1)
uses energy, makes protein, and the body’s sensitivity to other hormones.
Amino acid derivative hormones- each is derived from a ♦ THYMUS-
THYMUS- The thymus is the gland located in the mediastinum just
Hormones it works with are triiodothyronine and thyroxine, which are the ones
single amino acid. Amine hormones are synthesized by modi- beneath the sternum. Thymus is large in children, begins to atrophy at
that regulate the metabolism and also affect the growth and rate of the func-
fying a single molecule of tyrosine, it is produced by neurose- puberty, and, by old age, the gland is a vestige of fat and fibrous tissue.
tions of many other body systems. (1)
It is Considered to be primarily a lymphatic organ, but the hormone
cretory cells and by neurons, epinephrine and norepineph-
thymosin has been isolated from thymus tissue. Thymosin hormone-
rine. Produced by the thyroid gland and are synthesized by ♦ Parathyroid Gland: are located on the thyroid gland within the neck. The
stimulates the development of T cells(1)
adding iodine to tyrosine. (1) function of the gland would be controlling the amount of calcium inside the
bones and controlling blood. Parathyroid hormone is used to regulate calcium ♦ GASTRIC AND INTESTINAL MUCOSA- The gastric and intestinal mucosa is
MUCOSA-
Hormones signal a cell by binding to the target cells specific
the mucous lining of the GI tract contains cells that produce both endo-
receptors in a lock and key mechanism. Different Hormone levels. When calcium levels are too low, there is more parathyroid hormone
crine and exocrine secretions. GI hormones such as gastrin, secretin,
receptor interactions produce different regulatory changes produced and when there is too much calcium, a lesser amount of parathy-
and cholecystokinin- pancreozymin (CCK) play regulatory roles in coordi-
within the target cell through chemical reactions. (1) roid hormone is produced. (1)
nating the secretory and motor activities involved in the digestive pro-
cess. Ghrelin- hormone secreted by endocrine cells in gastric mucosa;
Lock and key: A hormone acts only on cells that have recep- ♦ Adrenal Glands: They are located on top of both kidneys, and are responsible
stimulates hypothalamus to boost appetite; slows metabolism and fat
tors specific to that hormone because the shape of the recep- for releasing hormones in response to stress through corticosteroids synthe-
burning; may be a contributor to obesity(1)
tors specific to that hormone because the shape of the recep- sis. The hormones they work with which are those that are released are corti-
tor determines which hormone can react with it. (1) sol, decreasing bone formation and suppressing the immune system. Cate- ♦ HEART-
HEART- The heart has a secondary endocrine role. Hormone-producing
cholamine is another hormone being epinephrine, norepinephrine, and dopa- cells produce atrial natriuretic hormone (ANH). ANH’s primary effect is to
mine for a fight or flight situation. There are also androgens which controls oppose increases in blood volume or blood pressure’; also an antagonist
to ADH and aldosterone.(1)
the development of male characteristics such as their sex organs. (1)